The present application relates to surgical fasteners and instruments for approximating and fastening tissue and, more particularly, to suture anchors and associated instruments for endoscopically attaching sutures to tissue.
The working channel of a flexible endoscope typically has a diameter in the range of about 2.5 to about 4 millimeters. Current staplers and suturing devices cannot be easily redesigned to work through such small openings. In addition, performing procedures by way of the working channel does not easily permit using two instruments positioned at different angles with respect to the wound site in order to “pass and catch” a needle and apply sutures.
Various clips, suture fasteners and anchors have been developed such that physicians (e.g., gastroenterologists) may endoscopically close perforations in the gastrointestinal tract resulting from, for example, ulcers or polypectomy. One type of suture anchor is known as a “T-tag” fastener. The T-tag is a small metallic pin with a suture attached at the middle. The physician may load the T-tag into the end of a cannulated needle of an applicator that may be inserted through the working channel of a flexible endoscope. The physician may push the needle into the tissue near the perforation and implant the T-tag into the tissue with the attached suture trailing through the working channel and out the proximal end of the endoscope. After two or more T-tags are attached to the tissue near the wound in this manner, the physician may pull the sutures to oppose the tissue around the wound. The physician may then fasten the sutures together by applying a plurality of alternating, right and left overhand knots using a knot pushing device or by applying a knotting element or other type of fastener through the working channel of the endoscope.
In order for T-tags to resist pull-out from the tissue when the attached suture is tensioned, the T-tag should rotate after ejection from the cannulated needle to be approximately perpendicular to the attached suture. An issue typically associated with anchors such as the T-tag is that if the anchor is implanted within tissue layers, rather than through tissue layers such that the anchor cannot reorient as described, it is possible for the T-tag to be easily pulled from the hole created by the penetrating needle.
Another issue typically associated with current suture anchors such as the T-tag is the occasional situation in which the anchor comes out of the distal end of the cannulated needle while the applicator is manipulated into the endoscope and towards the wound site.
An issue typically associated with current suture anchor applicators is the risk that nearby organs may be accidentally injured by the needle of the applicator. The physician normally cannot see anatomical structures on the distal side of the tissue layers when the needle is being pushed through the tissue layers. Therefore, there is a risk that adjacent organs may be accidentally injured by the penetrating needle.
In addition to addressing the above issues, it may be desirable to provide an improved suture anchor that is magnetic resonance imaging (MRI) compatible. For example, the anchor may be formed from a non-ferrous material.
Accordingly, there is a need for an improved suture anchor that may be securely retained in a suture anchor applicator until deployment into the tissue near a wound. In addition, there is a need for a suture anchor with improved resistance to pull-out from tissue, whether implanted within tissue layers or through tissue layers. Furthermore, there is a need for an improved suture anchor and suture anchor applicator that helps to prevent accidental injury to nearby anatomical structures during deployment of the anchor into tissue near a wound site. Finally, there is a need for an improved suture anchor that may be formed from a non-ferrous material in order to be MRI compatible.